Observer Support for DistilledPagePrefs

chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java
index 60e87b154f6646cd6d780cdbaf3964edb601ef90..cf39057a5c7a11356aad0bd2eb3b8f759c22c1d7 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java
@@ -7,36 +7,110 @@ package org.chromium.chrome.browser.dom_distiller;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.test.UiThreadTest;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.shell.ChromeShellTestBase;
 import org.chromium.components.dom_distiller.core.DistilledPagePrefs;
 import org.chromium.components.dom_distiller.core.DomDistillerService;
 import org.chromium.components.dom_distiller.core.Theme;
+import org.chromium.content.browser.test.util.UiUtils;
 
 /**
  * Test class for {@link DistilledPagePrefs}.
  */
 public class DistilledPagePrefsTest extends ChromeShellTestBase {
 
+    private DistilledPagePrefs mDistilledPagePrefs;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        startChromeBrowserProcessSync(getInstrumentation().getTargetContext());
+        getDistilledPagePrefs();
+    }
+
+    private void getDistilledPagePrefs() {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            public void run() {
+                DomDistillerService domDistillerService = DomDistillerServiceFactory.
+                        getForProfile(Profile.getLastUsedProfile());
+                mDistilledPagePrefs = domDistillerService.getDistilledPagePrefs();
+            }
+        });
+    }
+
     @SmallTest
     @UiThreadTest
     @Feature({"DomDistiller"})
     public void testGetAndSetPrefs() throws InterruptedException {
-        startChromeBrowserProcessSync(getInstrumentation().getTargetContext());
-        DomDistillerService service = DomDistillerServiceFactory.
-            getForProfile(Profile.getLastUsedProfile());
-        assertNotNull(service);
-        DistilledPagePrefs distilledPagePrefs = service.getDistilledPagePrefs();
-        assertNotNull(distilledPagePrefs);
-        // Check default theme.
-        assertEquals(distilledPagePrefs.getTheme(), Theme.LIGHT);
+        // Check the default theme.
+        assertEquals(mDistilledPagePrefs.getTheme(), Theme.LIGHT);
         // Check that theme can be correctly set.
-        distilledPagePrefs.setTheme(Theme.DARK);
-        assertEquals(Theme.DARK, distilledPagePrefs.getTheme());
-        distilledPagePrefs.setTheme(Theme.LIGHT);
-        assertEquals(Theme.LIGHT, distilledPagePrefs.getTheme());
-        distilledPagePrefs.setTheme(Theme.SEPIA);
-        assertEquals(Theme.SEPIA, distilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.DARK);
+        assertEquals(Theme.DARK, mDistilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.LIGHT);
+        assertEquals(Theme.LIGHT, mDistilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.SEPIA);
+        assertEquals(Theme.SEPIA, mDistilledPagePrefs.getTheme());
+    }
+
+    @SmallTest
+    @Feature({"DomDistiller"})
+    public void testSingleObserver() throws InterruptedException {
+        TestingObserver testObserver = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserver);
+
+        setTheme(Theme.DARK);
+        // Assumes that callback does not occur immediately.
+        assertNull(testObserver.getTheme());
+        UiUtils.settleDownUI(getInstrumentation());
+        // Check that testObserver's theme has been updated,
+        assertEquals(Theme.DARK, testObserver.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserver);
+    }
+
+    @SmallTest
+    @Feature({"DomDistiller"})
+    public void testMultipleObservers() throws InterruptedException {
+        TestingObserver testObserverOne = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserverOne);
+        TestingObserver testObserverTwo = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserverTwo);
+
+        setTheme(Theme.SEPIA);
+        UiUtils.settleDownUI(getInstrumentation());
+        assertEquals(Theme.SEPIA, testObserverOne.getTheme());
+        assertEquals(Theme.SEPIA, testObserverTwo.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserverOne);
+
+        setTheme(Theme.DARK);
+        UiUtils.settleDownUI(getInstrumentation());
+        // Check that testObserverOne's theme is not changed but testObserverTwo's is.
+        assertEquals(Theme.SEPIA, testObserverOne.getTheme());
+        assertEquals(Theme.DARK, testObserverTwo.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserverTwo);
+    }
+
+    private static class TestingObserver implements DistilledPagePrefs.Observer {
+        private Theme mTheme;
+
+        public TestingObserver() {}
+
+        public Theme getTheme() {
+            return mTheme;
+        }
+
+        public void onChangeTheme(Theme theme) {
+            mTheme = theme;
+        }
+    }
+
+    private void setTheme(final Theme theme) {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            public void run() {
+                mDistilledPagePrefs.setTheme(theme);
+            }
+        });
     }
 }